Antidepressants are supposed to work by fixing a chemical imbalance, specifically, a lack of serotonin in the brain. Indeed, their supposed effectiveness is the primary evidence for the chemical imbalance theory. But analyses of the published data and the unpublished data that were hidden by drug companies reveals that most (if not all) of the benefits are due to the placebo effect. Some antidepressants increase serotonin levels, some decrease it, and some have no effect at all on serotonin. Nevertheless, they all show the same therapeutic benefit. Even the small statistical difference between antidepressants and placebos may be an enhanced placebo effect, due to the fact that most patients and doctors in clinical trials successfully break blind. The serotonin theory is as close as any theory in the history of science to having been proved wrong. Instead of curing depression, popular antidepressants may induce a biological vulnerability making people more likely to become depressed in the future.
Irving Kirsch offered the above information in a publication obtained from the US National Library of Medicine. He is the Associate Director of the Program in Placebo Studies and a Lecturer in Medicine at Harvard Medical School. He is also Professor Emeritus of Psychology at the Universities of Hull and Plymouth in the United Kingdom, and a few others in the United States. Needless to say, he’s done a lot of research, and his revelations above should be read by anybody taking, or considering taking, antidepressant drugs.
The Effectiveness of Anti-Depressant Drugs Compared To Placebo;
In a 2002 study conducted by Kirsch and his team of researchers, published in The American Psychological Association’s Prevention & Treatment, it was discovered that 80 percent of the effect of antidepressants, as measured in clinical trials, could be attributed to the placebo effect. The difference between the response of the drugs and the response of the placebo was less than two points on average on a clinical scale that goes from fifty to sixty points. This is a very small difference, and is, according Kirsch, clinically meaningless:
I assumed that antidepressants were effective. As a psychotherapist, I sometimes referred my severely depressed clients for prescriptions of antidepressant drugs. Sometimes the condition of my clients improved when they began taking antidepressants; sometimes it did not. When it did, I assumed it was the effect of the drug that was making them better. Given my long standing interest in the placebo effect, I should have known better, but back then I did not.
Analyzing the data we had found, we were not surprised to find a substantial placebo effect on depression. What surprised us was how small the drug effect was. Seventy-five percent of the improvement in the drug group also occurred when people were give dummy pills with no active ingredient in them.
The response from critics was harsh, who emphasized that antidepressants have been evaluated in many trials and their effectiveness well documented.